31362d1a43
Streaming.cs 789 -> 330. Moved the go-live/record/health operation bodies into a new MainViewModel.Streaming.Operations.cs partial (459 lines: StartSession, BeginRecordOnly, BeginGoLive, StartRecordFile, PrepareAndStartLiveAsync, PollHealthAsync/OnHealthPollTick/ApplyHealthIssue, StopStream, FinalizeRecordingAsync, UniquePath, Choose/ResetRecordFolder, DefaultRecordFolder, OnFramePumpFailed/HealthUpdated, ApplyHealth, ResetHealth, BuildEncoderOptions). Streaming.cs keeps state, quality/resolution tiers, session timer, command declarations. Pruned dead usings in both files. Zero behavior change; build 0 warnings; 246 pass, only the 2 known failures. Docs: ViewModels/index.md Phase 3 tracker updated in same commit.